Update README.md

Adding a "Not For All Eyes" tag since it's sensitive content; thank you for understanding.

README.md

@@ -9,6 +9,7 @@ tags:
 - furry
 - e621
 - nsfw
+- not-for-all-audiences
 ---
 <div style='background: #ffdddd; padding:0.5em;'>
 Warning: This model is NOT suitable for use by minors. The model can/will generate X-rated/NFSW content.